FIGS. 11A and 11B are a plan view and a side view of conventional surface-mounted type coin-shaped storage cell 501 disclosed in patent document 1. Storage cell 501 includes storage element 110, such as a secondary battery or a capacitor, negative terminal 111 connected with a negative electrode of storage element 110, and positive terminal 112 connected with a positive electrode of storage element 110. Terminals 111 and 112 have solder-plated layers 113 formed thereon. Terminals 111 and 112 have swaged portions 114 at their edges to be soldered easily.
Conventional storage cell 501 requires a large mounting area since negative terminal 111 and positive terminal 112 protrudes outward from storage element 110. Cell 501 can hardly have a small size and a large capacitance for use in a small product, such as a portable device.    Patent document 1: JP2002-170551A